1. Field of the Invention
The present invention relates to a method and apparatus for sensing the temperature of a heat-generating component of a computer system.
2. Description of the Related Art
Computer systems include many electronic components generate waste heat as a by product of their normal functions. Since excessive heat can lead to component failure, significant efforts are made to design and operate computer systems to prevent components from reaching high temperatures. The most common approach to this problem is the use of forced air convection through computer chassis. For individual computers, sufficient cooling may be achieved using a single fan to circulate room temperature air through the enclosure. However, data centers generally require computer room air conditioning (CRAC) systems and fans that operate within individual chassis or racks.
Fans are necessary to make sure that air is circulated through each unit in an appropriate direction and at an appropriate flow rate. The direction of air flow is generally established during installation of the fan based on the direction of the motor and fan blades. The air flow rate is determined by the speed of the motor, the size of the fan blades, and the number of fans being used. However, the fans are also known to produce high volumes of noise and to consume a significant portion of the electricity used in a data center. Accordingly, it is not only important that the fans provide sufficient cooling, it is important that the fans are not run at excessive speeds.
Variable speed motors may be used in conjunction with a controller to adjust the fan speed as necessary. Typically, the temperature of an important heat-generating component, such as a processor, is measured with a thermocouple and communicated to a controller. The controller then monitors the processor temperature and adjusts the fan speed to achieve an air flow rate that prevents the processor from getting too hot. This type of temperature control requires mounting a thermocouple as close as possible to the heat-generating component. Unfortunately, this typically requires customization of the motherboard.
It would be desirable to have a system that could sense air temperature at one or more locations within a computer chassis independent of the position of the thermal sensors. It would also be desirable to have a system that reduced fluctuations in temperature measurements of the thermal sensors.